... Mastocarpus papillatus (C. Agardh) Kütz. is a common intertidal red alga occurring along the west coast of North America from Baja California to Alaska. Sequencing of both the chloroplast-encoded rbcL gene and the nuclear ribosomal internal transcribed spacer (ITS) regions of ~200 specimens from California to Alaska revealed that M. papillatus is actually a complex of at least five species. All fi ...